The etiology of idiopathic scoliosis remains obscure. Although it is known to be inherited in a polygenetic manner with variable transmission, consistent abnormalities have not been found. Among the various etiologies considered have been abnormalities in proteoglycan metabolism, muscle imbalance, variations in growth disturbance, and suggestions of abnormal neurologic innervation. At the University of California, Davis, there exists a group of inbred chickens which develop scoliosis. In these chickens there is increased solubility of collagen, signs of increased collagen metabolism and changes in stress relaxation patterns of spinal ligaments and tendons. The changes would suggest that there are problems in collagen cross-linkage or type distribution. Comparable studies in humans have resulted in similar findings, including increased hydroxyproline excretion. Scoliotic chickens and suitable controls will be studied both at various ages and with various degrees of severity of the disease. The cross-linking pattern of collagen will be investigated in tendon, bone, cartilage, and vertebrae. We also intend to fully charcacterize collagen in the scoliotic animal model and from scoliotic human tissue.